英国CITY空气质量传感器 A3OZ气体检测模块
- 格式：pdf
- 大小：42.17 KB
- 文档页数：2
Ozone/Nitrogen dioxide EnviroceL® Specification
A3OZ EnviroceL
®
This sensor is one of a range for monitoring gases at levels found in the environment. It is designed to
give accurate readings of O3 or NO2 in ambient air.
Performance Characteristics
Nominal RangeMaximum OverloadExpected Operating LifeOutput SignalResolution at 20°CTemperature RangePressure RangePressure CoefficientT90 Response TimeRelative Humidity RangeTypical Baseline Range(pure air)Maximum Zero Shift(+20°C to +40°C)Typical Long Term OutputDriftRecommended LoadResistorBias VoltageRepeatabilityOutput Linearity0-10ppm
100ppm
Two years
2.2 ± 0.5 µA/ppm
20ppb
-20°C to +50°C
Atmospheric ± 10%
No data
<40 seconds
15 to 90% non-condensing
0 to 0.1ppm equivalent
0.1ppm equivalent
<10% signal loss/year in air
33Ω
Not required
1% of signal
Linear
Polycarbonate
22g
None
Six months in CTL container
0-20°C
12 months from date of
despatch
Physical Characteristics
Material
Weight
Position Sensitivity
Storage Life
Recommended
Storage Temperature
Warranty Period
N.B.All performance data is based on conditions at 20°C,
50%RH, and 1013mBar
Cross-Sensitivity Data
Carbon monoxideNitrogen DioxideChlorineSulphur DioxideHydrogen SulphideNone
100%
100%
None
None
All tolerances ±0.15mm unless otherwise stated.
A3OZ shown with side tags and gold pins.
Do not solder to pin connections
41.2mm
1
0
.
5
m
m
1
7
.
8
m
m
3.0mmPin
Projection
Ø1mmon
34.2PCD
60°
Reference
3MountingHoles
Equispacedon34.4PCD
Ø3.0mm
SensingCounter42.5mmAuxiliary
Non-connected
pin
27.7mm
nominal
Outline Dimensions
深圳市深国安电子科技有限公司
地址：广东省深圳市龙华新区牛栏前大厦Ｃ５０７
网址：ｗｗｗ．ｓｉｎｇｏａｎ．ｃｏｍ ｗｗｗ．ｓｉｎｇｏａｎ．ｃｏｍ．ｃｎ ｗｗｗ．ｓｈｅｎｇｕｏａｎ．ｃｏｍ
蒋小姐：１３４ ２８７６ ２６３１ 电话：８６ ７５５－８５２５８９００
Circuitry required
The A3OZ EnviroceL differs from standard three electrode sensors by the introduction of
a second working electrode, known as the Auxiliary. A suitable operating circuit is shown
below.
When no gas is present, there is a small zero gas (baseline) signal from each electrode.
Upon exposure to nitrogen dioxide/ozone, the
sensing
electrode produces a signal
proportional to the concentration of gas. Virtually all the gas is reacted on contact with this
electrode, so the auxiliary electrode remains largely unaffected and hence the signal
remains at its baseline level. It can therefore be assumed the
auxiliary
signal is wholly
attributed to the baseline.
The baseline signal of both electrodes is slightly affected by changes in atmospheric
conditions (e.g. temperature). However as both are subject to the same conditions, any
shift in baseline on the sensing electrode will be followed by a similar shift in the auxiliary.
Hence by comparing the two signals any baseline changes may be compensated.
Evaluating the nitrogen dioxide/ozone concentration of a sample from the two signals is
a straightforward subtraction:-.
Let:IS= Sensing electrode signal;
IA=Auxiliary electrode signal;
Igas=Baseline compensated nitrogen dioxide/ozone signal.
ThenIgas=IS - I
A
Figure 1.
A3OZ Operating Circuit
IC1 - This amplifier
should have either a low
offset or have its offset
nulled out. The PMI OP-
77, OP-90, Intersil or
Teledyne 7650, and
Linear Technology
LT1078 are all suitable.
IC2, IC3 - This amplifier
acts as a current to
voltage converter and its
offset performance is
less critical. The OP-77
or similar is a suitable
choice
Recommended value of
R
load
is given in the
specification overleaf.
Counter
Reference
10K0µ1IC1-+-+10K
-
+
10K
10R
10K
10R
1K
AUXILIARY
SENSING
Sensing
Auxiliary
IC2
IC3
J177J177
V+
V+
10K
深圳市深国安电子科技有限公司
地址：广东省深圳市龙华新区牛栏前大厦Ｃ５０７
网址：ｗｗｗ．ｓｉｎｇｏａｎ．ｃｏｍ ｗｗｗ．ｓｉｎｇｏａｎ．ｃｏｍ．ｃｎ ｗｗｗ．ｓｈｅｎｇｕｏａｎ．ｃｏｍ
蒋小姐：１３４ ２８７６ ２６３１ 电话：８６ ７５５－８５２５８９００
